Process for the manufacture of a feed material from lettuce



Feb. 13,11940. H. A. sMl'rH 2,190,176

PROCESS FOR THE MANUFACTURE 0F A FEED MATERIAL FROM LETTUCE Filed Aug.. 13, 1957 /f en? INV ENT OR. Herv/"g A. '5/77/7//7 ATTORNEY.

Patented Feb. 13, 1940 UNITED STATES PATENT oFFlcE j PROCESS FOR THE `MIAN'UFAC'I'UR.

E ora FEED MATERIAL FROM LETTUCE Henry A. Smith, Berkeley, Calif., assignon, by

mesne assignments, to

National Oil Products Co., Harrison, N. J., a corporation of New Jersey Application August 13, 1937, Serial No.` 158,892

sible and the lettuce packing shed operators pay to have the material hauled away as waste.

I have determined that this lettuce can bev made into a suitable feed for animals,poultry and the like, one having a high value because of its considerable protein and fat content.

I have found that lettuce can be suitably disintegrated in a vertical hammer mill, such a mill being known as a Reitz disintegrator. Upon zo feeding lettuce into such a mill, the lettuce is thoroughly'disintegrated, being torn apart with many of the cells in the lettuce being broken open leaving the residue in a suitable condition for dewaterng. Upon separating the solid from z5 the liquid residue, the liquid fraction recovered has a suspended solid content. I have found that this solid content can be recovered and that it provides a valuable feed or a feed supplement because of its mineral protein and fat content.

It is in general the object of the present invention to provide a process for the utilization of waste lettuce.

Another object of the present invention is to provide an animal and poultry feed material from lettuce.

Another object of the invention is to provide a process for the recovery of the suspended solid content carried in the liquid fraction of lettuce.

The invention includes other objects and features of advantage, some of which, together with the foregoing, will appear hereinafter wherein the present manner of practicing the invention is disclosed. The draw' g is a diagrammatic representation of the present process.

Lettuce, either waste lettuce. cull heads, or the like, or surplus lettuce heads are passed to a disintegrator 6 wherein the lettuce is torn apart and thoroughly disintegrated so that the lettuce is in a suitable condition for dewatering. Thereafter the lettuce is passed to a press 1, such as a Louisville press, a screw press, or a combination of the two, wherein the water content is reduced. 'I'he solid content, containing about water, is passed to a dryer 8 and a feed product is secured.

66 'I'his product is of rather a dark green color and has thel appearance similar to alfalfa leaf meal. An approximate analysis of this material indicates the following composition:

Per cent Protein 13.94 5 Fat 3.74 Fiber 20.17 Ash 19.89 Moisture 5.93

Carbohydrates, etc 36.33 10 The over-al1 yield of this product is about 4% of the total weight of the lettuce processed. r

The liquid fraction separated in the press 1 is green'in color, and contains a large amount of suspended solids. I believe that these solids consist mainly of plastids. 'I'he solids are so suspended in the liquid that under usual operating conditions they cannot be recovered or separated. 20 I have determined that these solids can be separated from the liquid and that they are of particular value. The separation of the solids can be eiected by centrifuging the liquid fraction, by coagulating the solids with reagents to alter the 25 pH to the iso-electric point, or else by heating the material until coalescence occurs. A temperature of`100 C. usually suffices. Heating with steam in an open vessel is ordinarily suflcient. This last is preferred because of its simplicity and 30 effectiveness. l

Upon heating the liquid the suspended material collects on the top in the form of a cake. The remaining liquid is drained off'from the cake and the sludge ltered in the press to remove most 35 of the water. The collecting and-separation of the solids is indicated at l0 in the drawing, while the filtration of the material is indicated by filter 9. The solid residue from the filter 9 is dried in a dryer Il. This material, when dry, is 40 found to have approximately the following composition:

Per cent Protein 5 Fat 12 Fiber 2 Ash 10 Moisture 5 Carbohydrates, etc 36 50 In addition, the material is found to have a vitamin G content of about 5 gammas per gram.

'Ihis material can be used as such or added to 55 ously mentioned.

The suspended solids are also useful as a carotin and chlorophyl source. These can be extracted by the usual methods of extraction.

I claim: l A

1. A process for manufacture of an animal feed from lettuce comprising disintegrating and pressing the lettuce to separate a liquid fraction therefrom containing suspended solids, separating said suspended solids from said fraction, and dewatering said solids to provide a feed material.

2. A process for manufacture of an animal feed from lettuce comprising disintegrating and pressing the lettuce to separate a liquid fraction therefrom i containing suspended solids. heating said liquid fraction to cause said suspended solids to collect into a mass and separating said suspended another feed -or to the dried lettuce-feed previsends from solids to provide a feed material.

3. A process i'or manufacture of 'an animal ieed #from lettuce comprising mechanically disinsind fraction. and dewatermg said 

